set colored-stats ignores $LS_COLORS

Question

Problem

Bash <tab> autocompletion ignores $LS_COLORS variable and uses default color values.

Setting

I have a dircolors file and just the following declarations in .bashrc:

eval `dircolors $HOME/.config/bash/dircolors`

bind 'set colored-stats on'
bind 'set colored-completion-prefix on'

alias ls='ls --group-directories-first --color=auto'

The ls output is correctly colored by colors from $LS_COLORS and coloring for tab autocompletion is turned on. However tab autocompletion ignores $LS_COLORS and uses some default value (screenshot):

Context

I am on macOS 13.2.1, using Apple Terminal. GNU bash (5.2.15) and GNU ls (9.1, coreutils) installed via macports.

Question

Interested in any pointers about how to start solving this isssue?
Maybe someone can point me to which source files determine the logic behind color-coding autocompletions in bash?
Any tips are appreciated.

Answer 1

This is behavior implemented in the GNU Readline Library. Readline parses LS_COLORS only when initializing the library and coloring is enabled, and not afterwards; if coloring is disabled when initializing Readline (after reading inputrc), LS_COLORS is ignored and Readline will use its default colors. To reproduce this issue I wrote this example C program, which you can compile with -lreadline.

readline_test.c:

#include <stdio.h>
#include <stdlib.h>

#include <readline/readline.h>

int readline_puts(void)
{
    char *in;

    if ((in = readline("> ")) != NULL) {
        puts(in);
        free(in);
    }

    return in != NULL;
}

int main(int argc, char **argv)
{
    if (!readline_puts())
        exit(EXIT_FAILURE);

    // use coloring after Readline was initialized
    rl_variable_bind("colored-stats", "on");

    if (!readline_puts())
        exit(EXIT_FAILURE);

    return 0;
}

$ gcc readline_test.c -o readline_test -lreadline
$ mkfifo myfile1
$ touch myfile2
$ ./readline_test
> myfile<tab>
myfile1 myfile2
> myfile
myfile
> myfile<tab>
myfile1 (yellow, Readline default for pipes) myfile2 (normal)

But when setting LS_COLORS to display pipes in other color and changing main to:

int main(int argc, char **argv)
{
    // enable colors before Readline is initialized
    rl_variable_bind("colored-stats", "on");

    if (!readline_puts())
        exit(EXIT_FAILURE);

    if (!readline_puts())
        exit(EXIT_FAILURE);

    return 0;
}

$ gcc readline_test.c -o readline_test -lreadline
$ ./readline_test
> myfile<tab>
myfile1 (configured color) myfile2 (normal)

---

To take LS_COLORS into account in Bash you can enable colors in your ~/.inputrc:

$if Bash
set colored-stats on
$endif

Note that updates to the LS_COLORS variable still won't affect Readline coloring, to update colors you have to restart Bash either opening another terminal session or using exec /bin/bash.